It is common knowledge by now that UV rays from the sun cause a lot of damage to the eye. UV rays are located above the violet portion of the visible light spectrum and its main source is sunlight. There are three main categories of UV, that is, UVA, UVB, and UVC. UVA has a longer wavelength, which allows it to pass through normal glass easily. The information below is worth knowing about sunglasses lens types.
Whether this form of UV is injurious to the eye or not is a matter of contention among scientists. However, the second class of UV rays is the most dangerous to the eyes. UVB causes the most damage to the eyes and are the reason it is important to wear sunscreen and sunglasses because they cannot pass through. UVC rays do not reach the earth because they are blocked by the atmosphere.
Since UVB rays can damage the eye, it is always necessary to wear sunglasses as a protective measure. Other than acting as a protective gear for UVB rays, sunglasses also help prevent a number of defects of the eye. For example, people who have eye conditions such as long-sightedness or myopia require glasses to see well at long and close range respectively. Lenses are necessary in order for these glasses to work well.
There is a wide range of lenses, which are used to achieve different effects when worn. Some examples of sunglass lens types include aspheric, bifocal and trifocal, Hi-Index, photochromic, polarized, polycarbonate, and progressive. Aspheric lenses are made with a complex front surface that changes in curvature gradually from the center towards the edge. They are designed to correct small distortions in vision. They are convenient to wear and carry because they are lighter and thinner.
On the other hand, bifocal lenses are usually made for correcting both short-sightedness and far-sightedness. Far-sightedness is corrected by use of the lens on the upper part of the glasses while the glasses on the lower part are meant for correcting short-sightedness. Old people are usually prescribed these lenses since their near vision is weakened due to aging. Trifocal lenses usually incorporate into a bifocal lens the ability of a person to see objects that are a few feet away.
Photochromic lenses are made in a manner that they become dark when they come in contact with sunlight. This adaptation makes them suitable for individuals who would otherwise need to carry multiple sunglasses for different situations. They are available in all lens designs and materials. That means that one can find bifocals, trifocals, and hi-index lenses that are also photochromic.
Polarized lenses are designed to reduce the glare that comes from surfaces such as water surfaces, glass, and snow. This makes images to appear clearer and sharper. One can get them in both prescription and non-prescription sunglasses. They can be worn indoors by people who are sensitive to light. Post-cataract surgery patients make very good candidates for glasses with polarized lenses.
Active individuals should go for polycarbonate lenses. This is because these lenses are impact-resistant and resilient. Most parents buy their children these lenses because kids always damage sunglasses.
Whether this form of UV is injurious to the eye or not is a matter of contention among scientists. However, the second class of UV rays is the most dangerous to the eyes. UVB causes the most damage to the eyes and are the reason it is important to wear sunscreen and sunglasses because they cannot pass through. UVC rays do not reach the earth because they are blocked by the atmosphere.
Since UVB rays can damage the eye, it is always necessary to wear sunglasses as a protective measure. Other than acting as a protective gear for UVB rays, sunglasses also help prevent a number of defects of the eye. For example, people who have eye conditions such as long-sightedness or myopia require glasses to see well at long and close range respectively. Lenses are necessary in order for these glasses to work well.
There is a wide range of lenses, which are used to achieve different effects when worn. Some examples of sunglass lens types include aspheric, bifocal and trifocal, Hi-Index, photochromic, polarized, polycarbonate, and progressive. Aspheric lenses are made with a complex front surface that changes in curvature gradually from the center towards the edge. They are designed to correct small distortions in vision. They are convenient to wear and carry because they are lighter and thinner.
On the other hand, bifocal lenses are usually made for correcting both short-sightedness and far-sightedness. Far-sightedness is corrected by use of the lens on the upper part of the glasses while the glasses on the lower part are meant for correcting short-sightedness. Old people are usually prescribed these lenses since their near vision is weakened due to aging. Trifocal lenses usually incorporate into a bifocal lens the ability of a person to see objects that are a few feet away.
Photochromic lenses are made in a manner that they become dark when they come in contact with sunlight. This adaptation makes them suitable for individuals who would otherwise need to carry multiple sunglasses for different situations. They are available in all lens designs and materials. That means that one can find bifocals, trifocals, and hi-index lenses that are also photochromic.
Polarized lenses are designed to reduce the glare that comes from surfaces such as water surfaces, glass, and snow. This makes images to appear clearer and sharper. One can get them in both prescription and non-prescription sunglasses. They can be worn indoors by people who are sensitive to light. Post-cataract surgery patients make very good candidates for glasses with polarized lenses.
Active individuals should go for polycarbonate lenses. This is because these lenses are impact-resistant and resilient. Most parents buy their children these lenses because kids always damage sunglasses.
About the Author:
Check out an impressive catalog of different sunglasses lens types by touring our web pages today. To know more about our prescription lenses and our custom repair solutions, click the links at http://www.sunglassreplacementlenses.com right now.
0 komentar:
Posting Komentar